Percutaneous balloon

ABSTRACT

An intra-aortic balloon designed for percutaneous insertion. An inflatable intra-aortic balloon of reduced diameter, when inflated, has its proximal end secured to a catheter. A stylet extends through said balloon and is anchored in a tip provided at the distal end of the balloon. The stylet extends from said tip through said balloon and through at least a portion of said catheter. A balloon coupling comprised of a &#34;Y&#34; member is provided with a linear bore communicating with said catheter and a branch bore intersecting with said linear through bore. The stylet extends partially into said through bore and said branch bore and has its proximal end coupled to a control knob assembly threadedly engaged with the rear end of said branch-bore and movable when rotated in a first direction to simultaneously twist and elongate the intra-aortic balloon and when rotated in the reverse direction to simultaneously untwist and relieve the elongated condition. The twisting of the control knob, twists the stylet and the tip, causing the balloon to be twisted as it is being lengthened. The lengthening of the balloon prevents the balloon membrane from &#34;doubling up&#34; as it is twisted. The twisting operation significantly reduces the exterior balloon diameter enabling the balloon to fit through a small diameter percutaneous sheath inserted into an artery. The screw threads on the balloon luer are precisely designed to limit the maximum travel preventing an operator from turning the stylet beyond the &#34;wrapped for insertion&#34; position and also preventing the stylet from moving beyond the totally unwrapped position after the balloon is properly placed in the patient. A catheter adapter slidably mounted on the catheter is inserted into a sheath collar which retains the adapter within the collar and provides a blood-tight seal preventing blood from exiting from the sheath.

This is a division of application Ser. No. 253,680, filed April 13,1981, now U.S. Pat. No. 4,422,447 issued Dec. 27, 1983.

FIELD OF THE INVENTION

The present invention relates to intra-aortic balloons and moreparticularly to novel apparatus for adapting an intra-aortic balloon forpercutaneous insertion by means which simultaneously elongates andtwists the intra-aortic balloon for insertion and simultaneouslyuntwists and eases the aforesaid elongation in readiness for use of theballoon in the operative position.

BACKGROUND OF THE INVENTION

Intra-aortic balloons are well known in the art as medical appliancescapable of providing assistive pumping for a weak heart. Conventionalintra-aortic balloons have been described for example in U.S. Pat. No.4,016,871 issued Apr. 12, 1977 to the present inventor. Traditionally,intra-aortic balloons, as well as other catheters, were both insertedinto a patient and removed therefrom through the use of a surgicalprocedure. The tedious surgical technique led to the development andadoption of the Seldinger Catheterization Technique which is now a wellknown and well established procedure in daily use since at least 1976and involves a percutaneous invasion of the arterial system withoutresorting to a surgical procedure.

The availability of the Seldinger Technique led to the development of anintra-aortic balloon described in the British Publish Patent ApplicationNo. GB 2,037,166 published July 9, 1980 in which a technique isdescribed wherein an intra-aortic balloon is manually twisted to reduceits outer diameter, a vacuum is drawn to retain the intra-aortic balloonin the twisted, reduced diameter state. The twisted intra-aortic balloonis then inserted into the patient percutaneously, employing theSeldinger Technique. After insertion, the vacuum condition is removed topermit use of the balloon.

The above-mentioned design has led to a number of disadvantages in thatno specific technique is available for insuring that the intra-aorticballoon has been completely untwisted once it is moved to the operativeposition. In addition, the need for manual twisting of the ballooncomplicates the insertion procedure and increases the time required toperform the procedure. Also there is no means for positively assuringthat the balloon will be untwisted after insertion. Through the use ofthe novel technique and apparatus of the present invention, it ispossible to eliminate the step of drawing a vacuum in the balloon as isrequired in the prior art techniques.

BRIEF DESCRIPTION OF THE INVENTION

The present invention is characterized by comprising a novelintra-aortic balloon designed for percutaneous insertion and whicheliminates the disadvantages of the aforementioned prior artpercutaneous balloons.

The present invention is characterized by comprising an intra-aorticballoon terminating in a tip arranged at its distal end and being joinedwith a catheter at its proximal end. A slender stylet is anchored withinthe aforesaid tip and extends rearwardly through said intra-aorticballoon and into said catheter. A holder is arranged a spaced distanceinwardly from the point of connection between said catheter and theproximal end of said balloon and is provided with a substantially linearthrough bore which communicates with said catheter and a branch borehaving a forward end communicating with the through bore and a rearwardend which is tapped for threaded engagement with a threaded membersecured at one end to an adjustment knob. The aforementioned styletextends partially into the forward end of the through-bore and into thebranch bore of said stylet receiving holder and has its proximal endanchored to the aforementioned threaded portion of said control knob.Positive and negative pulsatile pressure for respectively inflating anddeflating said intra-aortic balloon, communicates with said balloonthrough said through-bore and said catheter. The stylet is sufficientlyslender relative to the inner diameter of the catheter and the balloonto avoid impeding the inflation and deflation operation of theintra-aortic balloon.

In order to prepare the balloon for insertion, the aforementionedcontrol knob is twisted, simultaneously causing the stylet, the tip andthe balloon to undergo twisting. The direction of twisting of thecontrol knob and its threaded portion also linearly moves the distal endof said stylet away from the proximal end of said balloon causing anelongation thereof. Thus the balloon simultaneously undergoes twistingand elongation. The twisting action significantly reduces the outerdiameter of the balloon, making it extremely advantageous forpercutaneous insertion through a small diameter sheath of a percutaneousinsertion set. The simultaneous elongation of the balloon prevents thetwists formed in the balloon material from "doubling up" so as to retainthe aforesaid reduced low profile outer diameter of the balloon.

The balloon is then inserted percutaneously. After insertion iscompleted, the aforementioned control knob is twisted in the reversedirection causing its threaded member, the stylet, the tip and theballoon to untwist. At the same time, the stylet and tip move rearwardlytoward the proximal end of the balloon thus easing the aforementionedelongation condition. The number of turns which the knob is capable ofundergoing is precise, thus assuring that the balloon will be completelyuntwisted and will not be twisted in the reverse direction. Theintegrity of both the twisting and untwisting operation is assuredthrough the use of an extremely rugged reliable and yet slender stylet,preferably formed of a resilient and yet extremely durable stainlesssteel wire which, under life testing has shown to be capable of havingan extremely long, useful operating life, well beyond the life of theintra-aortic balloon itself.

The percutaneous sheath is provided with a collar which receives acatheter adapter slidably mounted on the balloon catheter. The adapteris retained within the interior of the sheath collar and provides ablood-tight seal which prevents blood from escaping from thepercutaneous sheath.

OBJECTS OF THE INVENTION AND BRIEF DESCRIPTION OF THE FIGURES

It is therefore one object of the present invention to provide a novelintra-aortic balloon designed for percutaneous insertion and includingmeans for positively wrapping and unwrapping the intra-aortic balloon.

Still another object of the present invention is to provide a novelintra-aortic balloon including means for positively and simultaneouslytwisting and elongating said balloon to provide a significantly reducedouter diameter which is extremely advantageous for percutaneousinsertion, said elongation preventing the twists in said balloon from"doubling up" and thereby increasing the outer diameter.

Still another object of the present invention is to provide anintra-aortic balloon advantageously adapted for percutaneous insertionand employing a stylet and means for rotating and linearly moving saidstylet in first and second opposing directions to respectively providethe balloon with a significantly reduced outer diameter advantageous forpercutaneous insertion and for positively untwisting said balloon to beassured of its proper and optimum operation after insertion.

Still another object of the invention is to provide a balloon forpercutaneous insertion and having a catheter adapter which cooperateswith a percutaneous sheath to provide a blood-tight seal and lock theadapter in the sealing position.

The above as well as other objects of the present invention will becomeapparent when reading the accompanying description and drawing, inwhich:

FIG. 1 shows a percutaneous balloon structure embodying the principlesof the present invention.

FIGS. 1a and 1b respectively show perspective views of an inflatedballoon and a twisted balloon ready for percutaneous insertion.

FIG. 2 shows a perspective view of the intra-aortic balloon couplingemployed in the assembly of FIG. 1.

FIG. 2a is an enlarged sectional view of a portion of the ballooncoupling of FIG. 2.

FIG. 3 shows a simplified diagram of the general manner in which apercutaneous insertion is made.

FIG. 3a is an enlarged sectional view of the percutaneous sheath shownin FIG. 3.

FIGS. 4a and 4b show simplified views of the intra-aortic balloonassembly useful in explaining the steps followed for percutaneousinsertion.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an intra-aortic balloon assembly 10 embodying theprinciples of the present invention and comprised of an intra-aorticballoon 12 formed of a pliable thin gauge plastic material which iscapable of stretching to only a minor degree to provide a controlledmaximum diameter when fully inflated. The forward end 12a of balloon 12is tapered as shown and terminates in a tip 14 at its distal end asshown. The rearward end of balloon 12 is similarly tapered at 12b and isthereafter of a constant diameter and defines the forward end 16a of acatheter outer shell 16. The catheter outer shell 16 and balloon 12 inthe preferred embodiment, is formed of one continuous outer shell,preferably of polyurethane, and without seams. The outer shell portion16 of the continuous sheath is provided with a thin, hollow inner shell17, preferably formed of thin gauge polyethylene. The inner and outershells extend rearwardly to the balloon coupling 20. The rearward ends16b and 17b of catheter shells 16 and 17 are force fittingly mountedupon the left-hand end 18a of the stepped connector 18 having outerdiameter portions 18a, 18b and 18c of increasingly larger diameters. End18c-1 of portion 18c is force-fittingly inserted into the left-hand endof a through bore 20a provided in balloon coupling 20 which is asubstantially rigid member preferably formed of a suitable plasticmaterial and having a substantially linear through bore 20a extendingfrom its left-hand end through the main body 20d thereof and through atapered rearwardly extending projection 20b. Second catheter 18' has itsleft-hand end 18a' force fittingly mounted upon a female extension luer23 having a barbed end 23a and a substantially cylindrical shaped bore23b extending through the length of the main body portion of luer 23 andbarbed projection 23a. The left-hand end of bore 23b is tapered at 23cin order to force fittingly receive the tapered projection 20b forcoupling the intra-aortic balloon 12 to a source of pulsatile pressure(not shown) for inflating and deflating balloon 12.

Coupling 20 is further provided with a diagonally aligned section 20cintegral with the main body portion 20d and provided with a branch bore20e communicating with the main through-bore 20a at a locationintermediate to the ends of bore 20a, said branch bore extendingrearwardly and communicating with an opening 20f in the rear wall 20g ofbranch section 20c. The rearward section 20e-1 of branch bore 20e is ofa reduced diameter. A shoulder 20e-2 is formed at the point wherereduced diameter bore 20e-1 meets the larger diameter bore 20e.

A threaded screw 22 threadedly engages tapped bore 20e-1. Asubstantially cylindrical-shaped solid body 24, integral with screw 22,has an enlarged diameter portion 24a relative to screw 22 and a smalldiameter portion 24b forming a shoulder 26 at the point where largerdiameter portion 24a joins reduced diameter portion 24b. The right-handend of screw 22 is provided with a manually operable adjustment knob 28integrally joined to screw 22 for turning screw 22 in the tapped portion20e-1 of bore 20e.

Resilient washers 37 and 39 may be provided to air tightly seal coupling20, preventing air from entering or leaving opening 20e when knob 28 isin either of its two extreme end positions.

In one preferred embodiment, balloon coupling 20 is preferably formed ofa plastic material such as, for example, nylon. As shown best in FIG.2a, bore portion 20e-1 and shoulder 20e-2 meet and form a sharp cornerat 20e-3. The shoulder 26 between enlarged diameter body portion 24a andreduced diameter portion 24b is preferably tapered. When knob 28 isrotated in the direction causing body portions 24a and 24b to move inthe direction of arrow B₁, the tapered or diagonally aligned shoulder 26bears against the sharp corner 20e-3 to assure a firm air andliquid-tight seal therebetween. Knob 28 is provided with a centrallylocated bore (not shown) and a radially aligned threaded boreintersecting with the aforementioned axially aligned bore. A set screw29 threadedly engages threaded bore 28a to secure knob 28 to bodyportion 24b-1 as shown in FIG. 2a.

A slender stylet 30 formed of a bendable and yet durable material suchas stainless steel, for example, has its forward end 30a fixedly securedand anchored within balloon tip 14. Stylet 30 extends rearwardly throughballoon 12, catheter 16, coupling member 18 and the forward portion ofmain bore 20a. The stylet 30 thereafter is gently curved and extendsinto branch bore 20e and has its rearward end 30b anchored to theleft-hand end of solid cylindrical member 24. Rearward end 30b of stylet30 is preferably silver soldered into member 24 so that any turningmotion and/or linear motion of member 24 is directly imparted to stylet30. Similarly as was described above, tip 14 is fixedly secured to theforward end 30a of stylet 30 so that any rotational and/or linearmovement experienced by stylet 30, is directly imparted to tip 14.

As was described hereinabove, in order to implant intra-aortic balloon12 through the use of a percutaneous insertion technique andspecifically the Seldinger Technique, a hypodermic needle (not shown) isinserted through the skin, and, in the case of intra-aortic ballooninsertion, the needle perforates the femoral artery 41, shown in FIG. 3.When blood spurts from the open external end of the needle, placement ofthe hypodermic needle (not shown) within the femoral artery 41 isconfirmed. A guide wire is then placed into the artery 42 by passing theguide wire through the center of the hollow needle and into the iliacartery bifurcation. The hypodermic needle is then removed while the wireis maintained in the aforesaid position within the artery. A dilator isplaced over the guide wire and advanced through the skin and into thefemoral artery in order to dilate (i.e. enlarge) the artery.Subsequently the dilator is removed and a larger dilator/sheath isadvanced into the artery over the guide wire. The guide wire is thenremoved, leaving the dialator/sheath 40 in place and extending throughthe femoral artery 41, available for insertion of a balloon catheterassembly 10 into the aorta without surgery. FIG. 3 shows the sheath 40arranged within the iliac artery 42, the forward (distal) end 40a beingopen. Sheath 40 extends rearwardly and through the puncture 42a formedin the femoral artery 41, by the hypodermic needle as was describedhereinabove, and extends outwardly through the skin 45. A coupling 44 isjoined to the rearward end 40b of sheath 40 and has an opening 44a forreceiving the intra-aortic balloon 12 and a catheter adaptor 60, as willbe more fully described.

The balloon insertion operation is as follows:

As one optional approach, the balloon 12 is dipped in a sterile salinesolution. As one optional approach, a stopcock 46 (see FIG. 4a), havingan opening at its rearward end 46a, is mounted to coupling projection20b and is placed in the open position. A syringe 48 is inserted intostopcock 46 to empty balloon 12. Thereafter, stopcock 46 is closed andthe syringe 48 is removed from the stopcock 46. The closure of stopcock46 prevents balloon 12 from being refilled with air.

As a preferred technique, the syringe and stopcock may be eliminated forpurposes of deflating balloon 12. As an alternative, balloon 12 issimply stripped by placing balloon 12 between the fingers and squeezingthe balloon while moving the fingers from tip 14 to point 50 as shown inFIG. 4a in order to empty the balloon of air. This technique ispreferred over the vacuum drawing technique since it has been found thatan excessive vacuum condition creases the balloon membrane and holds thefolded layers so tightly that the balloon 12 does not wrap well. Thewrapping of the balloon 12 has been found to be more effective andcompact when the contents of the balloon 12 are evacuated simply bystripping the balloon between the fingers, as described.

The knob 28 is rotated in the clockwise direction. The balloon 12 isheld at location 50 and tip 14 is gently rotated to assist the wind-up,i.e. the twisting of balloon 12. Balloon 12 is then stripped lightly bymoving the fingers along balloon 12 from point 50 toward tip 14 tosmooth out the balloon 12 and thereby minimize its outer diameter. Theelongation of balloon 12 prevents the twists in the balloon 12 from"doubling over". Balloon 12 is hollow except for the presence of stylet30, enabling the balloon 12 to wrap itself about stylet 30 which servesas the means for supporting the balloon 12 in its elongated state.

As shown in FIG. 2, the above steps are repeated until control knob 28can no longer be turned in the clockwise direction. This occurs when theleft-hand surface of knob 28 engages the rear surface 20g of coupling20.

Returning to FIG. 4b, thereafter balloon 12 is again briefly dipped intoa sterile saline solution, and tip 14 is inserted into opening 44a ofcoupling 44 and is pushed through coupling 44 and hollow sheath 40.Balloon 12 may be twisted counter-clockwise during insertion, as shownby arrow 54 in FIG. 3, only as needed during the insertion operation.

When balloon 12 is in the operative position, with tip 14 in the aorticarch, catheter adapter 60, described in detail in U.S. Pat. No.4,122,858 issued Oct. 31, 1978 to this inventor, is pushed along thecatheter 16 of intra-aortic balloon assembly 10 and into the opening 44ain percutaneous sheath collar 44.

As can best be seen from FIG. 3a, the opening 44a in percutaneous sheathcollar 44 is provided with a tapered wall 44b which communicates with ahollow interior 44c of larger diameter, forming the shoulder 44b-1. Thisarrangement enables catheter adapter 60 to slide along catheter 16 andpast the tapered wall 44b to enter into the hollow interior 44c. Thesheath 44 has some resilience in order to yield outwardly as catheteradapter 60 is pressed into opening 44a. As soon as the rearward surface60a of catheter adapter 60 clears the tapered side wall 44b, theyielding opening contracts, locking the right-hand surface of catheteradapter 60a by means of interior shoulder 44b-1. The percutaneous sheath40 has its rearward end 40b extending inwardly into the left-hand end ofpercutaneous sheath collar 44 and it is anchored within grooves 44d, theright-hand most end 40b-1 conforming to the shape of the recesses 44dprovided in collar 44 to secure the right-hand end of sheath 40 tosheath collar 44. The catheter adapter 60, as is described in detail inaforementioned U.S. Pat. No. 4,122,858, provides an air and liquid-tightseal between adapter 60 and catheter 16. The locking means in the formof shoulder 44b-1 and the rear surface 60a of catheter adapter 60cooperate to prevent catheter adapter 60 from being removed from collar44. The interior periphery of opening 44c forms a tight fit with theouter periphery of adapter 60 to form a blood-tight seal therebetween,preventing blood which may pass between sheath 40 and catheter 16 fromexiting through opening 44a.

Control knob 28 is then rotated counter-clockwise until it can no longerbe rotated in this direction. This counter-clockwise rotation untwistsballoon 12, completing the insertion operation.

As was mentioned hereinabove, to twist balloon 12, control knob 28 isrotated clockwise causing screw 22 and cylindrical body 24 to alsorotate clockwise, imparting clockwise rotation to stylet 30. Stylet 30,in turn rotates tip 14 causing balloon 12 to be twisted about stylet 30.

According to FIG. 1, simultaneously therewith the rotation of screw 22causes screw 22 to move linearly in the direction shown by arrow A1causing screw 22, member 24 and stylet 30 to move in the direction shownby arrow A2; thereby causing tip 14 to move away from balloon coupling20, to simultaneously elongate balloon 12 as it is being twisted, toprevent the twists being formed in balloon 12 from being "doubled over"whereby the twisted balloon 12 presents a significantly reduced outerdiameter making the intra-aortic balloon assembly 10 extremelyadvantageous for use in percutaneous insertion such as through the useof the above described Seldinger Technique.

To remove balloon 12 from the body, the balloon is deflated andsimilarly re-twisted by means of knob 28 and is then pulled back throughsheath 42.

The outer diameter of stylet 30 is extremely slender. In one preferredembodiment the diameter of stylet 30 is 0.026 inches, thus, stylet 30does not interfere with positive and negative pulsatile pressure pulsespassing through coupling 20, catheter 16 and balloon 12 during theoperation of intra-aortic balloon 12. A type No. 302 stainless steelwire which has been utilized for stylet 30 provides excellentperformance over long periods of time without failure. However, althoughstainless steel stylets are preferred, any other material exhibitingsimilar operating characteristics, may be employed if desired.

A latitude of modification, change and substitution is intended in theforegoing disclosure, and in some instances, some features of theinvention wil be employed without a corresponding use of other features.Accordingly, it is appropriate that the appended claims be construedbroadly and in a manner consistent with the spirit and scope of theinvention herein.

What is claimed is:
 1. An intra-aortic balloon assembly comprising:anelongated intra-aortic balloon means having a distal end terminating ina tip and a proximal end; said balloon means being formed of a materialwhich is substantially inelastic to substantially prevent elasticexpansion during normal inflation; coupling means having a through-borefor communicating pulsatile pressure to said balloon means; elongatedcatheter means coupled between the proximal end of said balloon meansand one end of said through-bore; the other end of said through-borebeing adapted for coupling to a pulsatile source for introducingpositive and negative gas pressure into said balloon means through saidthrough-bore and said catheter means for periodically inflating anddeflating said balloon means; stylet means extending through saidballoon means, said catheter means, and said coupling means and having adistal end coupled to said tip; said coupling means having a branch-borecommunicating with said through-bore; the proximal end of said styletmeans extending through a portion of said through-bore and into saidbranch bore; a manual operating knob assembly arranged external to saidcoupling means for rotating said stylet means and including control knobcoupled to rotatable threaded operating member; said coupling meansbranch bore having a tapped interior portion engageable with saidthreaded operating member for rotatably supporting said manual operatingknob assembly to permit rotation of said manual operating knob assemblyin first and second opposite directions to rotate said stylet means andthereby selectively twist and untwist said balloon means; and a firststop comprising a shoulder in said branch bore engageable with ashoulder on said threaded operating member for limiting rotation of saidmanual operating knob assembly in a first direction and second stopmeans comprising the end of said control knob engaging the adjacent endof said coupling member to limit rotation in a second direction tothereby limit the twisting and untwisting respectively of said balloonmeans to a predetermined amount.
 2. The intra-aortic balloon assembly ofclaim 1 wherein the engagement between said threaded member and saidbranch bore shoulder provides an air-tight seal.
 3. The intra-aorticballoon assembly of claim 1, wherein the engagement between said knobassembly and said coupling means provides an air-tight seal.